Working on a detail with a builder to add 1″ of polyiso to the exterior of an existing 2×4 wall in Zone 5.
Planning to install cedar singles as the sidewall material. Most often, it seems the drainage layer (water control layer) is behind the foam (b/w foam and sheathing). However, we would like to use a drain wrap as the air control layer with the added benefit of providing a small (very small) level of drain space behind the shingles.
Any issues with placing the drain wrap b/w the shingles and foam as opposed to installing the housewrap between foam and sheathing?
Happy New Years!
GBA Detail Library
A collection of one thousand construction details organized by climate and house part